Automatically operated door mechanism for a mixer,kneader,reactor or like machine



Aug. 26, 1969 B. A, LooMANs ET Al. 3,463,459 AUTOMAI'ICALLY OPERATEDDOOR MECHANISM FOR A MIXER, KNEADEH, REACTOR 0R LIKE MACHINE 3Sheets-Sheet 2 Filed Feb. l2, 1968 INVENTORS BERNARD A. LOOMANS RICHARDJ. BALAZER THOMAS l. ROSS CLARENC K. SCHERPlNG BY 'CAMA'.

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Aug. 26, 1969 B. A. LOOMANS ET AL 3,463,459

AUTOMATICALLY OPERATED DOOR MECHANISM FOR A MIXER, KNEADER, REACTOR ORLIKE MACHINE Filed Feb. 12, 196e s Sheets-sheet s S G RMR N fm OAESM nu.TMZSR ,.u` NOAOE MRW uw WLBLS llAm .S n @JAH m DM m RROC -m AAHN l N EHT f RC R El A .m TNIL. BR L w HIWHi C m eludlit.. Y x x B United StatesPatent O M 3,463,459 AUTOMATICALLY OPERATED DOOR MECHA- NISM FOR AMIXER, KNEADER, REACTOR OR LIKE MACHINE Bernard A. Loomans, Thomas I.Ross, Richard J. Balazer, and Clarence K. Scherping, Saginaw, Mich.,assignors to Baker Perkins Inc., Saginaw, Mich., a corporation of NewYork Filed Feb. 12, 1968, Ser. No. 704,601 Int. Cl. B01f 15/02 U.S. Cl.259-41 15 Claims ABSTRACT OF THE DISCLOSURE A continous mixer havinghousing means in the configuration of intersecting cylinders and aplurality of parallel shafts extending axially in the housing, radiallyaligned interwiping mixing paddles on the shafts shaped to also wipe thewalls of the housing upon rotation of the shafts, doors for the housingcurved to be wiped by the paddles when in closed position, one of thedoors being normally maintained in at least partly open position topermit the passage of material out the door while the other is normallymaintained in closed position, a control circuit for varying theposition of the partly open door according to the power required todrive the shafts in the same direction of rotation and at the samespeed, a control for periodically moving the partly open door to closedposition to permit a paddle to wipe the door and remove any accumulationof material thereon, and a control for opening the normally closed doorwhen the normally partly open door is substantially fully opened.

One of the prime objects of the invention is to provide a mixer having adischarge door assembly including one normally partly open gate or doorconfigured to be wiped by a mixing element which is controlled in amanner so that it is periodically closed to permit the mixing element towipe the door.

Another object of the invention is to provide a door of the characterdisclosed which is retained in a partially open position and regulatesthe flow of material being discharged from a continuously operatingmixer, and which automatically reacts to an emergency situation to openfully toempty the mixer of material.

Still another object of the invention is to provide a door assemblyincluding an upper gate and a lower gate, the bottom gate or door beingnormally closed and openable automatically in an emergency situationresponsive to opening of the upper gate or door to assist the upper doorin emptying the mixer.

Other objects and advantages of the invention will be pointed outspecifically or will become apparent from the following description whenit is considered in conjunction with the appended claims and theaccompanying drawings, in which:

FIGURE 1 is a fragmentary, sectional elevational view through the mixerof the invention, with the midportion of the mixer being broken away andomitted from the view for the sake of convenience;

FIGURE 2 is a transverse sectional view through the discharge end of themixer, taken on the line 2 2 of FIGURE l;

FIGURE 3 is a similar transverse sectional View taken through the mixeron the line 3 3 of FIGURE 1;

FIGURE `4 is `a fragmentary, sectional top plan view taken on the line 44 of FIGURE 2;

FIGURE 5 shows a typical electrohydraulic control system for the doorassembly.

3,463,459 Patented Aug. 26, 1969 ICC Referring now more particularly tothe accompanying drawings, wherein a preferred embodiment of theinvention only is illustrated, the mixer includes end base members 10mounting frame portions 11 on which the bed 11a of a horizontallydisposed mixer housing generally designated 12 is supported as shown. Itis to be understood that the mixer which will be described is acontinuous mixer of the character disclosed in Loomans et al., U.S.Patent No. 3,195,868 and in a similar manner inclutdes the figureS-shaped housing 12 which defines communicating upper and lowerintersecting, cylindrical chambers 14 and 15. While the `drawings do notindicate it, usually a jacket is provided around the casing 12 to hold acooling or heating medium in the manner disclosed in the patentmentioned. As FIGURE 1 indicates, the charge end of the barrel orhousing 12 is closed by an end plate 16, and a material supply hopper 17may be provided for moving material into the casing 12 through amaterial supply opening 18.

Extending axially through each of the chambers 14 and 15 in a concentricmanner are upper and lower mixer shafts 19 and 20, respectively, whichmay be journaled in suitable bearings 21 at the charge end of thehousing 12, and 22 at the discharge end. Keyed. on the front ends ofshafts 19 and 20 as in the aforementioned patent are worm sleeves 23 and24 which serve to advance the material from the charge end of thehousing 12 toward the opposite end thereof, and also keyed on the shafts19 and 20 are pairs of radially interengaging and interwiping upper andlower paddles 25 and 26, respectively, which wipe the Walls of thefigure 8-shaped housing 12 as well as one another.

As the drawings indicate, each of the paddles 25 and 26 is of generallylenticular shape and each pair of mating paddles 25 and 26 is ldisposedwith. the major axis of one paddle at right angles with respect to themajor axis of the other paddle, as illustrated particularly in FIGURE 3.The paddles 25 and 26 may be helically pitched in a direction to movethe material from the charge end of the mixer housing 12 toward thedischarge end and staggered helically so that they collectively alsoform worms moving the material toward the discharge end of the housing12. The continuous spiral feed screws 23 and 24 in cross section havethe same configuration as the paddles 25 and 26 and consequently theirrespective crests also Wipe the walls of the chambers 14 and 15 clean.The iianks and crests of each spiral feed screw are thus also wipedclean by the flanks and crests of the other spiral feed screw in thesame manner as are the flanks and crests of the paddles 25 and 26. Thefeed screw sections 23 and 24 are preferably pitched to provide a morerapid throughput of material than the pairs of paddles 25 and 26 wouldprovide, and insure the desired rate of throughput. With low viscositymaterials supplied under pressure by a metering device, it may bedesirable to replace the worm sections 23 and 24 with pairs of paddles25 and 26, and this may also be advisable when certain chemicalreactions are occurring in the mixer. The shafts 19 and 20 are driven inthe same direction of rotation and at the same speed Aby a drive shaft27 mounting a gear 28 in mesh with a gear 29 on the shaft 19, and a gear30 in mesh with a gear 31 on the mixer shaft 20.

THE DISCHARGE HOUSING At the discharge end of the housing a dischargehousing assembly generally indicated by the numeral 32 is connected toan end support wall portion 11' and includes a discharge casingsurrounding the discharge end of mixer housing 12 having side walls 33and 34 (FIGURE 2), end walls 35 and 36, and stepped top wall sections 37and 38 which join to the mixer housing 12, the Wall 37 being 3 joined tothe upper portion of mixer housing 12 by a wall 37a. The end wall 36 ofdischarge housing 32 closes the end of mixer housing 12 as well. AsFIGURE 1 indicates, the discharge housing assembly 32 is open at itslower end as at 39 and discharges to any suitable collecting orconveying device, dependent upon the mixing operation or reaction beingcarried on in the mixer housing 12. A divider plate 32a depends from theend of mixer casing 12.

THE DISCHARGE GATE ASSEMBLY As FIGURE 1 also illustrates, the portion ofmixer casing 12 which extends into the discharge housing 32 houses anend pair of paddle members 25 and 26' and reversely pitched, helicalworm or screw sections 40 and 41 fixed on the shafts 19 and 20 which arepitched to advance material in a direction toward the charge end of themachine in opposition to the flow of material therein. Provided withinthe discharge housing 32 are an upper rock shaft 42 and a lower rockshaft 43, di-sposed adjacent and parallel to opposite sides of the mixercasing 12. The shafts 42 and 43 are journaled in bearings `44 which maybe aixed to the casing or barrel 12 and mount discharge doors or gates45 and 46, respectively, on arms 47 which are keyed to the rock shafts42 and 43 as at 48. As FIGURE 2 particularly indicates, the gates 45 and46 have curvilinear inner surfaces as at 45a and 46a to conform to thecurvilinear coniiguration of the casing 12 and, when in the closedposition in which they are shown in FIGURE 2, eifectively seal theoppositely disposed side discharge openings 49 and 50 provided in thecasing 12. Pivotally mounted as at 51 on a bracket 52 secured to the endframe member 11 is the piston rod 53a of a hydraulic cylinder 53 whichcarries a cylinder 54 having a piston rod 54a pivotally connected as at55 to an arm 56 which is keyed to the rock shaft 42 as at 57. Alsopivotally mounted as at 58 on a bracket `59 secured on the opposite sideof end member 11 is a hydraulic cylinder `60 which has its piston rod 61pivotally connected as at 62 to an arm 63 keyed to the rock shaft 43 asat 64. As will later become clear, piston rod 53a is normally fullyextended to hold cylinder 54 in a position that allows it to open andclose gate 45, the piston rod 54a is held in a normally partly extendedor open position to provide a gate which is open to the extent e inFIGURE 2, |and the piston rod 61 is normally in the retracted positionin which it is shown in FIGURE 3 and holds the gate or door 46 in theclosed position in which it is shown in FIGURE 2. Access doors `65 and66 are releasably secured over openings 67 and 68 in walls 34 and 35,respectively, as shown in FIGURE 2, for the sake of convenlence.

THE ELECTROHYDRAULIC CIRCUIT At the left in FIGURE is an electricalcircuit and at the right a hydraulic circuit which is controlled by theelectrical circuit in a manner to be described. The drive motor fordriving `shaft 27, and through it shafts 19 and 20, is shown at 69 inthe electrical circuit connected through a current transformer 70 to anoptical meter relay 71 with an indicating pointer contact 71b andseparately adjustable high and low contacts 72 and 73, the so-calledhigh contacts 72 being normally open as shown and the contacts 73 beingalso normally open. The meter relay employed is one which is currentlyavailable `on the market and may comprise the type 195 meter relay soldby General Electric Company. Such meters conventionally include theindicating pointer, which is movable relative to a `scale yaccording tothe current being drawn and which opens and closes the low and highrelay contacts 73 and 72, respectively, at the limits of its travel inthe usual manner. Preferably, the so-called high and low contacts 72 and73 are carried by settable points whose position also can be variedrelative to the scale to set different limits.

Also connected in the electrical circuit adjacent the meter relayygenerally designated 71 is a motor driven timer generally designatedIT. Such timers are also currently available on the market and maycomprise the series 305B general purpose reset timer manufactured byAutomatic Timing & Controls, Inc., King of Prussia, Pa., U.S. The timedelay device IT is operative to provide a denite timed period duringwhich the door 45 is normally partly open. A valve IV for controllingthe open position of door 45 under normal circumstances has a solenoid76 which, when energized, operates to further open door 45. The valve IValso has a solenoid 77 which, when energized, operates to pass Huid tocylinder 54 to move the door 45 to a more closed position. At the rightend of FIGURE 5 in the hydraulic diagram, hydraulic fluid under pressureis shown as supplied to the valve IV through a hydraulic line 79 by ahydraulic power lunit comprising a pump 80 driven by a motor 81, pumpbeing connected to a reservoir 82. From valve IV a hydraulic fluidsupply line 84 leads through a ilow control valve 85 to the gateclosingside 86 of the hydraulic cylinder 54. Similarly, a hydraulic uid line 87leads from the gate-opening side 88 of the -cylinder 54 through a flowcontrol valve 89 back to control valve IV. Hydra-ulic line 90 connectsthe valve IV with reservoir 82.

Dependent on the particular setting of relay contacts 72 and 73 withrespect to the meter scale 71a, control valve IV will maintain thepiston rod 54a of cylinder 54 in a partly raised position and the door`45 in a partly open position so long as the power required to driveshafts 19 and 20 is normal. When the mixer shafts 19 and 20 are beingdriven normally under a normal power load, the pointer 71b of meter 71will be disposed approximately midway between the relay contacts 72 and73. When the pointer swings over to the high contacts 72, however,indicating that an undue amount of power is being utilized to driveshafts 19 and 20, contacts 72 are closed and solenoid 76 is energized topass fluid through line 87 to move the door 45 to a more open position.At this time, of course, solenoid 77 is deenergized. Conversely, whenpractically no power is being utilized to drive shafts 19 and 20, as ata time when the machine is starting up, the low side contacts 73 will beclosed, due to the presence of the meter indicator pointer 71b at thecontacts 73, and solenoid 77 will be energized to pass hydraulic fluidthrough line 84 to the cylinder 54 and move the door or gate 45 to amore closed position. At this time solenoid 76 is, of course,deenergized and hydraulic uid is free to exit through hydraulic line 87.

The hydraulic cylinder 54 is actuated to completely open the door orgate 45 in an emergency situation when an abnormally high current isrequired to drive shaft 27 and, when this occurs, the arm 56 depressesthe spring returned operating plunger 92 of a hydraulic valve 3V which1s operated to move fluid through a line 93 and ilow control valve 94 tooperate cylinder 60 and open door 46. Hydraulic fluid is supplied to thecontrol valve 3V through a hydraulic line 95 communicating with line 7 9and the valve 3V has a reservoir line 96. A similar line 9.7 leadsthrough a ow control valve 98 to the opposite side of the cylinder 60.The valve 3V normally maintains the door 46 closed and it is only whenplunger 92 1s depressed that hydraulic lluid is fed by the valve 3Vthrough hydraulic line 93 to raise the piston rod 61 of hydrauliccylinder 60 `and completely open the gate or door 46. This occurs onlyat a time when the gate or door 45 is already fully opened and serves topermit the extremely fast exit of material from the mixer in anemergency situation. Such a situation might occur, for instance, m apolymerization reaction to empty the machine rap1dly 1f the reactiongets out of control temperaturewlse.

Except when meter contacts 72a are opened (which occurs when pointer 71bcloses high limit contacts 72), the timer IT operates to periodicallyclose the top gate 45 so that it may be intermittently wiped by the pairof paddles 25', 26 and reverse screw sections 40 and 41, it beingunderstood that reverse worm sections 40 and 41 in cross section havethe same configuration as the paddles 25 and 216 to perform the wipingfunction in the same manner. The timer IT has a motor M driving a springreturned timer pointer p which moves from a preset position 1 governingthe time period through a rotary path to a second position 2. to open aswitch 98a. The motor M is coupled to the pointer by a clutch C1 whichreleases when contacts ITRc are opened so that the pointer can return aswill later appear. When the motor M of timer IT times out by openingswitch 980:, the companion timer switch 98h is closed and the solenoid99 of spring returned control valve 2V is energized so that hydraulicfluid is fed through a hydraulic line 103 and a flow control valve 105to the door closing side 104 of cylinder 53. A hydraulic line 100 leadsfrom the opposite, door opening side 102 of cylinder 53 through a owcontrol valve 101 back to the control valve 2V. Control valve 2V isprovided with the usual reservoir line 106 which communicates with thereservoir 82.

As FIGURE 5 indicates, a switch actuator 107 provided on the arm 56moves into engagement with the actuator arm of a switch ILS when arm 56on which it is mounted is pivoted downwardly to dispose door 45 inclosed position. Thus, when the gate or door 45 is moved to fully closedposition by the cylinder 53, the movement is sensed by limit switch ILS.Connected in circuit with the limit switch ILS is a timing relay ITRwhich has relay contacts ITRa with associated timing contacts IT Rb andcontacts ITRc, as shown. When the contacts ITRc are opened by relay ITR,the pointer p of timer IT is freed so that it may return (reset) tooriginal position. Simultaneously, the contacts ITRa close to holdsolenoid 99 energized after timer IT contacts 98b reset to their openposition. The pneumatic timing contacts ITRb hold solenoid 99 energizedfor a time period of approximately one second or whatever time isrequired to insure that the interior'surface 45a of door 45 is cleaned.When the timing contacts ITRb of relay ITR open, solenoid 99 isdeenergized and valve 2V is free to return to original position.Cylinder 53 is thereby returned to original position, the gate 45 isopened to a position again governed by the control valve IV, limitswitch ILS is released, and timer ITR is reset by the opening of limitswitch contacts ILS. When the pointer p of timer IT is returned to itsoriginal position, contacts 98a and 98b close and open, respectively,contacts ITRc reclose when timer ITR resets, and the clutch solenoid Cof timer IT is energized at this time to recoupled the timer pointer pto motor M so that the cycle repeats.

It is to be noted that when the timer IT times out and the door 45 isclosed for cleaning, the complete cylinder 54 is carried alongdownwardly with its piston position unchanged. Later, when cylinder 53reopens the gate 45, the gate or door 45 will return to the same controlposition. The ow control valves 101 and 105 for cylinder 53 are set toprovide relatively fast movement so that the closing of gate 45 will notlast long enough to raise the motor load and upset the control positionof cylinder 54.

As the control circuit indicates, both manual and automatic control ofthe upper gate or door 45 is provided. With the control selector switchC at hand (the position x of the bridge members shown in solid lines),the top door v45 is controlled by watching the motor load indicatorpointer of meter 72 and pressing the open or close push button 107 or108, respectively, to position the door 45 as desired. Manual gateoperation will be used during start-up to position the gate 45 to apredetermined amount of material is present in the machine. Whenquick-close button 109 can be used to close the top gate 45 quickly forcleaning. When the button 109 is released, the gate 45 will return toits previously positioned opening. The olf position of the controlbridge members is indicated at y and the automatic position at z.

In operation, both gates 45 and 46 are initially closed, of course,until the machine is charged and a predetermined amount of materialpresent in the machine. When this occurs the amount of current requiredto rotate shafts 19 and 20 will increase and control valve IV will beoperated through energization of solenoid 76 to open the gate 45 to apredetermined open position in which it is normally maintained, as shownin FIGURE 2. Thereafter, as long as normal flow conditions aremaintained in the mixer and normal current is required to operate shafts19 and 20, valve 45 will be retained in this normally open positionexcept that it will periodically be closed by the timer IT operatingthrough valve 2V. The gate 45 is closed under these conditions for asufficient period of time for the top gate 45 inner surface to be wipedclean. Only in an emergency situation will door 45 be completely opened,and at this time the bottom door 46 will also be completely opened forthe period of time during which the unusually high current is requiredto revolve shafts 19 and 20. When the high current situation is relievedby emptying of the material rapidly through both gates 45 and 46, theIgate 45 will return to a partially open position while gate 46 returnsto closed position.

We claim:

1. In a mixer, kneader, reactor or like machine: housing means in theconfiguration of intersecting sylinders; a plurality of parallel shaftsextending axially in said housing means and having interwiping materialagitating means thereon shaped to also wipe the walls of said housingmeans upon rotation of said shafts; means for driving said shafts in thesame direction of rotation and at the same speed; door means in saidhousing means configured to be wiped by said agitating means when inclosed position; means normally holding said door means in a positionremoved from closed position to permit the passage of material throughsaid door means; and means for periodically moving said door means toclosed position to permit said agitating means to wipe said door meansand remove any accumulation of material therefrom.

2. The combination defined in claim 1 in which electrically controlledmotor means drives said shafts; said door means is mounted to move tovarious positions in which it varies the amount of material passed; andcontrol means is provided for varying the position of said door meansaccording to the power required to drive said shafts.

3. The combination defined in claim 2 in which said door means is movedaway from said housing means upon an increase in the power required.

4. The combination defined in claim 1 in which said agitating meanscomprises radially aligned, generally lenticular paddles on said shafts,the interwiping paddles being angularly displaced 5. The combinationdefined in claim 4 in which said paddles are helically disposed to feedmaterial toward one end of said housing means; and reverse-hand wormmeans on said shafts at said end feed material in an opposite direction;there being discharge casing means leading from said housing means atthe juncture of said worm means and paddle means and housing said doormeans.

6. The combination defined in claim 1 in which said door means isprovided in the upper part of said housing means and a second door meansis provided in the lower part of said housing means; said second doormeans being normally in closed position; and control means for openingsaid second door means when said first door means reaches a fully openposition.

7. The combination defined in claim 6 in which electrically controlledhydraulic rams separately move said door means and second door means toopen and closed positions.

8. The combination of claim 7 in which said housing means is in theconfiguration of an upright figure 8 and the door means and second doormeans are on opposite sides of the housing means.

9. In a mixer, kneader, reactor or like machine: housing means; shaftmeans extending axially in said housing means and having materialagitating means thereon; means for driving said shaft means; door meansin said housing means configured to be wiped by said agitating meanswhen in closed position; means normally holding said door means in aposition removed from closed position to permit the passage of materialthrough said door means; and means for periodically moving said doormeans to closed position to permit said agitating means to wipe saiddoor means and remove an accumulation of material therefrom.

10. In a mixer, kneader, reactor or like machine: housing means; shaftmeans extending axially in said housing means and having materialagitating means thereon; means for driving said shaft means; gate meansfor said housing means for controlling the discharge of materialtherefrom; means for sensing the amount of current required to operatethe shaft means; and means for moving the gate means away from thehousing means to increase the outflow therefrom when said sensing meanssenses that the current requirement is greater than a predeterminedrequirement.

11. The combination defined in claim 10 in which the sensing meansincludes contacts set at high and low power requirement limits.

12. In a mixer, kneader, reactor or like machine: longitudinallyextending housing means; shaft means extending axially in said housingmeans and having mixing element means thereon; means for driving saidshaft means; upper gate means in one end of said housing means; meansnormally holding said upper gate means in a position removed frornclosed position to permit the passage of material through said uppergate means; lower gate means for said end of the housing means; andcontrol means operable in response to said upper gate means reaching apredetermined position removed from closed position to open said lowergate means.

13. In a mixer, kneader, reactor or like machine, housing means; shaftmeans extending axially in said housing means and having materialagitating means thereon; means for driving said shaft means; dischargedoor means in said housing means; means normally holding said door meansin a position removed from closed position to permit the passage ofmaterial through said door means; means for sensing the amount of powerrequired to drive said shaft means; and means for holding said doormeans in an open position when said power requirement increases.

14. In a mixer, kneader, reactor or like machine: housing means; shaftmeans extending axially in said housing means incorporating mixingelement means thereon; means for driving said shaft means; door means insaid housing means configured to be wiped by said agitating means whenin closed position; and means for automatically periodically moving saiddoor means from an open to closed position, and returning said doormeans, to permit said agitating means to wipe said door means and removeany accumulation of material therefrom.

15. The combination defined in claim 14 in which a first fiuid pressureoperated cylinder moves said door means to more open or more closedpositions dependent on the power required to drive said shaft means; andsaid means for automatically periodically moving said door meansincludes a second fiuid pressure operated cylinder means carrying saidfirst fluid pressure operated cylinder means.

References Cited UNITED STATES PATENTS 2,994,100 8/1961 Comes 259-41 X3,099,040 7/1963 Matsuoka 259-41 X 3,195,868 7/1965 Loomans 259-104ROBERT W. JENKINS, Primary Examiner U.S. Cl. X.R. 259-6

